This proposal focuses on neural substrates of orthographic and phonological processes that must be honed in the developmental acquisition of reading skill. Changes in these processes emerge through development as a young reader gains experience with written words. Behaviorally, adults show processing advantages (i.e. increased speed and/or accuracy), less evident in children, for letters over visually similar letter-like objects, and for legal letter strings over non-letter strings or illegal letter strings. This processing advantage suggests that increasing experience enables a reader to extract specific, orthographic information about the visual features that form letters and words. In concert, extensive evidence suggests that phonological processing provides important support for reading development, and that its interplay with orthographic processes varies as skill develops. Information about how the developmental acquisition of reading expertise relates to putative orthographic and phonological processing regions in the brain should provide an important neurobiological foundation for understanding typical (and atypical) reading development, and inform more targeted future education and remediation strategies. The first specific aim tests the hypothesis that visual processing regions of the brain will show increasing specialization with the developmental acquisition of reading skill. The second specific aim tests the hypothesis that concomitant with increasing reading skill and orthographic specialization comes decreasing reliance on phonological processing mechanisms. The third specific aim uses functional connectivity MRI and graph theory analysis to characterize developmental differences in reading networks between adults and children. Additional proposed analyses include a longitudinal component where a cohort of subjects have repeated scans over a five year period, exploration of individual differences using a multivariate approach combining stable measures of reading/cognitive skill with imaging and in-scanner performance parameters, and an exploration of developmental sex differences. PUBLIC HEALTH RELEVANCE: This proposal focuses on neural substrates of orthographic and phonological processes that must be honed in the developmental acquisition of reading skill. Information about how the developmental acquisition of reading expertise relates to putative orthographic and phonological processing regions in the brain should provide an important neurobiological foundation for understanding typical (and atypical) reading development, and this basic knowledge can be used to inform more targeted future education and remediation strategies.